Desk lamp



FIG. 1 is a perspective view of a desk lamp showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof.

The features shown in broken lines illustrate unclaimed portions of the desk lamp. 

The ornamental design for a desk lamp, as shown and described. 